Kotlin, I dont understand why you must attached the "type" when you use "this" keyword

[JoneLoveIT]

 

[jj9987]

Every function must have a defined return type. It is simply for clarity reasons to keep things the same everywhere. Even if you use "this", it can cause confusion what exactly is "this", that is being returned.

[JoneLoveIT]

22 minutes ago, jj9987 said:

Every function must have a defined return type. It is simply for clarity reasons to keep things the same everywhere. Even if you use "this", it can cause confusion what exactly is "this", that is being returned.

but why function print in the screenshoot have no return type?

[JoneLoveIT]

31 minutes ago, JoneLoveIT said:

but why function print in the screenshoot have no return type?

and why do you still need : Order when it already in Order class?

[jj9987]

5 hours ago, JoneLoveIT said:

but why function print in the screenshoot have no return type?

Because print function does not return anything, it only triggers a print output to standard output.

4 hours ago, JoneLoveIT said:

and why do you still need : Order when it already in Order class?

Doesn't matter where the function is or what it belongs to. It still must define what it returns. A function in Order class can also return just a string. For example, you can have a function in the Order class, that is named getItems() and returns itemList, that is of type MutableList<Item>.